Virginia's Declaration of Rights was drawn upon by Thomas Jefferson for the opening paragraphs of the Declaration of Independence. It was widely copied by the other colonies and became the basis of the Bill of Rights.
The ridges found in flexible metal duct create turbulence and will diminish airflow. NEVER use 4 dryer duct or any plastic duct on a range hood installation. The minimum size duct allowed on most range hoods is 3 Â¼ by 10 which is equivalent to 6 round. More powerful hoods require even larger duct sizes up to 10 round. Consult the specifications for the model you have chosen.
Distance between the cooktop and range hood. The height from the top of your cooktop to the underside of your range hood is a very important measurement for safety reasons. In Australia, the minimum height of the range hood above an electric cooktop is 600mm. The minimum height of the range hood above a gas hob is 650mm.